Not sure what your budget is, but you could probably get away with the excellent fabfilter pro L2 limiter and pro q3 eq. Izotope ozone is also very good, and you may be able to snag a deal on a light version of it. If those are still above your budget you could always grab the venerable waves L2 maximizer and use it gently like 1-3db max, of limiting. I find audiodeluxe.com to be the cheapest place on tbe net for pluggins since they add an extra discount to pretty much everything when yoy add it to your cart, and always have the lowest starti g price available at tbe given time.

The advantage to fabfilter is amazing sound, versatility, and unlimited installs. You'll find yoyrself using fab in the mix and master. Ditto for ozone although its not quite as pristine as fab, it does have some more mastering specific functions.

I use ozone and Fabfilter Pro L2 for mastering,.. but I won't pretend and call them mastering, maybe pseudo mastering.
Why ? because I know very well that I don't have the room, equipement and knowledge/experience to call myself Mastering engineer ME.

Altought in theory, even stock pluggins could be use for mastering. An extreemly well tuned room and monitoring system is essential to an ME's job.
Using gizmo and gadgets softwares only expose us to the fact that we aren't ME yet and some never will... I'm talking to myself as well here.

Depending on the level of distribution of your music, I strongly recommand you at least check for a real ME and see if the investment is truely out of reach. You could be surprised..

OP: If you have a single track I can do a full analog master at no charge. Here's a few samples of my work:

Before: https://www.dropbox…
After: https://www.dropbox… Sweater - ESM Master 24-44.wav?dl=0

Before: https://www.dropbox… Coming to Town For Master02.wav?dl=0
After (MP3 - little harsh :(): https://www.dropbox…

These days the automated mastering websites are actually starting to get reasonably good at doing a basic mastering job on a budget.
I created what I believe was the first automated intelligent mastering system back in 2003, but I decided it wasn't a good decision to allow an automated system to fully master a track, so instead I incorporated it into my mastering flow to help create more efficiency and consistency for my clients. Even though I constantly updated the system with more and more improvements to its abilities, I still hold to that today. However, when you're stuck to a tight budget or you need to get something out quickly, the automated mastering systems available today have become an option that you can consider without worry about it completely sucking the life out of your music (the way they did when these sites first started appearing a few years ago).
If you're not comfortable doing your own mastering and you have a tight budget I would definitely give them a try. The price is so low you can't really go wrong. If you don't like it, you're only out a few dollars.
The big ones are LANDR and emastered, plus a few others. I even eventually released my system as a fully automated mastering website at - https://cdpmastering.com
Sorry to those engineers out there who are frustrated by these automated mastering sites calling themselves "professional mastering". We all know that's not true. But, to the average musician who's simply trying to release something and get the ball rolling with their music career we have to be honest about their needs. And for many of them these automated sites provide good enough results at their current level. It is what it is and it's futile to try and fight it. The best thing we can do is continue to help those who are truly looking for actual "professional mastering" to see that they need an experienced pro mastering engineer to assist them, and politely direct those who simply need their music a little buffed up and beefed up to one of these automated sites and say "Good luck with your music! Come back and see me when you're ready to take it up to the next level."
FYI, I've been a pro mastering engineer for nearly 20 years and I've worked on thousands of songs - https://www.crazymastering.com - just to lend relevancy to what I'm posting here.

Here's an interesting test :

I've saved that video and will certainly be giving that a watch.

I think a human interaction is needed to do a good job. It needs to stay an art form, in my opinion...
The mastering engineer will react with his experience and emotions to the content and will take actions a machine won't do.
For exemple making the choruses wider or having different dynamic control for different part of the song.
There is so many content aware moves we will do compared to an algorithm.

Of course, if I get a customer coming in with a bad karaoke.mp3 track to sing on.. Chances are I won't propose a professionnal mastering service...
(I usually do a pseudo master myself for those times) ;)

No amount of clever AI can deal with artistic intention, or deal with a whole album sequencing, or make good artistic decisions, so the real mastering boys are safe for a while. As far as the robot, tried 'em all, and Aria actually did do a pretty good job of EQ on the track I tested with. Mind you, the client preferred the homebrew rough so YMMV!

Here is a list with some of the best Plugins for your Mastering Chain

Hi,

1] attached video gives the impression to be exhaustive (very rare). It shows mainly that most so-called ´algorithmic’ solutions are made up with maximizers and tools like Ozone which squash many details out of final track, too.

2] cheap mastering can be obtained from not-established ME’s, you should find some in your area (or in Latin America).

3] by focusing on a lesser number of tracks you should find the budgetting cut you seek. As for serious yet not too expensive ME’s, I found these 2 :

nevo.eu

https://www.harmoni…

As for matricing @ home, my advise is to opt out for ANY treatMents like plugins which affect deliberately the stereo field of the mix [until you get a pro’ software].
But feel free to create your own M/S matrix, this is the most flexible approach to discerning treatments [which don’t mess with the stereo field, and you won’t have messed w/ it by matrixing M/S].

As for personalized mastering :
www.projetvojvod.wo…