Martial arts are something I've spend a lot of time in my life doing . . . 1 year Aikido, 5 years WTF Taekwondo, 3 years Muay Thai, 2 years Judo, 5 years Brazilian Jiu Jitsu . . . some boxing and wrestling mixed in there at various points too.
Good training places for martial arts are more expensive than big box gyms. Big box gyms can pay trainers just about nothing because they don't care about the qualifications of their staff. The skills and dedication of the staff at a martial arts place will determine how good the training you get is. Around here, about 100 - 150$ a month is a decent price for one. There is no alternative. IT IS NOT POSSIBLE to learn to fight by yourself. If you try, you will develop bad habits that will set you further back than people who are brand new to the sport. I've taught some classes, and have seen some horrific bad habits caused by self-training. Without a partner and someone to correct your bad technique you will be wasting your time.
I'm glad that you seem to be interested in focusing on one particular aspect of martial arts rather than trying to combine things right from the start. My experience has been that having a strong base in something really helps you develop better and will be less confusing than trying to learn multiple unrelated things all at once. You don't want to be a jack of all trades - master of none.
Judo clubs are typically cheaper. Many are run at cost or very close to it. Typically the instruction is done by someone who knows what he's doing . . . and judo clubs are competitive environments which is vital in developing technique that works. If you can't perform your technique against a resisting opponent, your technique is useless. While I love judo, it doesn't train you for MMA competition. Especially after the BS Kodokan rule changes that came into play a few years back (DQ in competition for touching below uke's belt on attack). In judo you will not get experienced sprawling, defending single/double leg takedowns, you will get minimal and only very basic groundwork and your classes will very heavily emphasize grip stuff that's just not important in MMA (no jacket to grip).
You fight the way that you train. The latest set of rules for competition Judo have really hurt the martial art . . . many traditional techniques are now not allowed (Kata-guruma, Morote-gari, Kuchiki-taoshi, Sukui Nage, Kibisu-gaeshi, etc.) in an attempt to make competition judo look prettier. Because of this, it's common for judo clubs to avoid training these techniques.
That said, some judo clubs are good for MMA training . . . I've been to a club that did Kosen judo where they do a no gi (effectively wrestling) days every now and then, and where they spend more time focusing on groundwork. It was very similar to BJJ training. If you can find a decent instructor who teaches and allows older techniques in sparring rather than focusing on what's currently allowed in tournaments you will learn more useful throws as well and will develop some experience sprawling. In all honesty though, you would be much better served grappling for MMA with a Brazilian Jiu-Jitsu place . . . as they will be set up to focus on all this stuff by default. Straight up wrestling would be better for you than judo for throws because of the reduced focus on gripping the gi to execute your technique. I like gi work quite a bit, but if your goal is to fight without it, you need to train for that goal.