I'm considering this game. Are the 'founder mechs' that good? Are they only available now, or after release? Which package makes sense, or play for free?
The founder mechs are good.
The founder mechs have a special skin no one else can get for that mech, but that isn't the selling point of them. They give you a 25% bonus to in game currency earned each match (which is pretty damn good considering you need to repair your mech after each match and buy more ammo as well). They also don't take up any of your 4 garage spots and have their own (you will be able to buy more garage slots for real money). Last, they are the "prime" version of those mechs, you need to own the prime version of a mech to unlock its "variants" (same mech but with different hardpoints/equipment/armor so can be customized totally different and will play a lot different from one another).
So the founder mechs give you a 25% bonus to in game currency when you use them, they save you money by already unlocking that mechs variants, save you money by not having to worry about a garage spot for that mech, and they will have unique skins that are only for those founder mechs (though I don't care much about that part).
How much the mechs themselves cost (same mech just not with the founder bonus's) depends on the class. Light mechs cost like 3 million in game currency, all the way up to the big boys assault mechs that cost 11-12million. The only real idea how much real money this is worth is one of the devs said that the $80 of ingame currency you receive when you buy eliter/legendary equals out to 8-10 medium mechs (medium is the second class of mech, order of them is light, medium, heavy, assault)
You might be like, well I just want the prime mech and don't care about the variants, and that is all good, but as you play you earn exp for each mech as well as pilot exp. You spend this exp in a skill tree that gives you minor improvements but you can only get to the next tier or skills to unlock if you have at least 3 of that mechs type (say an Atlas prime and 2 variants of it) base skills unlocked with exp to go to the next level up to get better skills for the mech you do want the skills for. Make sense?