c2d era laptop. first step if you haven't yet, swap the hdd for a low-cost sata ssd if you can. if you have some homeless sodimms, up the ram, too, if it won't cost anything to do it.
if you're going with mx, you want the fluxbox spin; or opt for antix with icewm instead.
otherwise start with a debian base install (no de or extra sw at install), then add only what you need. peppermint is another option--a basic debian with xfce out-of-the-box and little else. it's what i've been using lately on similar hardware.
for something 'different', you could look at slax.
agreed. games read a lot of random data. performance won't be nearly as 'good' as op expects.
the difference of $50 matters that much for op, i think that not spending anything would be the more prudent choice.
that said, if it were me i'd raid-0 two of them and keep the third as a single drop-in replacement for when that array dies; containing a full backup of the array's contents kept up-to-date with every major patch the games on it gets.
that's the whole reasoning behind having LMDE. seems a little redundant today; but within a release or two mint may very well be only based on debian itself, with the way canonical is steering ubuntu.
there was different trick-or-treat "events" on saturday and sunday here, so as few as 360 if the same schedule holds for those things next year (weekend before a halloween that falls on a 'school night').
every. damn. day. the worst might be i get to the outer door at the office, ready to go outside. and i just stop. 30 seconds later, shake my head a bit and go 'oh yea. i'm leaving now'.
at least once a month i have to dodge some moron passing on the right (and through empty, marked, parking spaces..which is not legal), someone who is either turning left or had stopped for me---in a marked crosswalk, and literally right in front a fucking sign that says 'stop for pedestrians'.
it always seemed to storm whenever we went camping when i was a kid, and that's what all the campers looked like when you're stuck in a little tent during one.
there's enough ways around charges of 'discriminating' based on the disallowed criteria of household income or race, that it will still be 'business as usual' for providers. they'll use other excuses, such as differences in local market (competition) and population/customer density, or the 'extreme' costs of upgrading aging infrastructure in previously-"avoided" areas, which would be 'allowed'.
better to support via votes, funding, spreading-the-word, and volunteer efforts, than to label oneself a 'pirate' (or anything, really) on voter registrations, which are public data here. i'll stick with "independent" on that form, tyvm.