158292
First of all, you need to assess the threat that your expecting your armour to take it up against. If your oponent is using T-34's, it doesn't matter wether you're buying an outdated Patton, or a modern Abrahams, they're both going to #Rek the T-34.
In that case, you obviously buy the Patton, because it's cheaper.
If the choice of tank IS going to influence your defense's chances of victory against any invaders, you need to look at your budget. (Not how much money you HAVE, but how much money you CAN GET AWAY WITH SPENDING)
Can you afford the better tank? If so, then do it.
If you can't afford the better tank right now, then there are still a few things you need to look at.
Firstly, is it economically workable to purchase the cheaper tank, in the long run? Sometimes, the cheaper alternative seems viable enough, at the time, but if your oponent is going to get bigger, badder toys in his force, then you may actually not end up with more money in your pockets, as you'll be needing to buy the better tank, anyway, whilst the cheaper tank you bought has been loosing it's re-sell value.
In this case, it may be better to wait, and stick with what you have, and, if need be, invest in a cheap emergency solution, such as MPAT's (man portable anti tank) equipment, and buy the better tank later.
If you really can't spare the money for the better tank, and really need one now, you're going to have to choose for the cheaper tank. But, even then, you're not done yet.
You can always see if it's viable to give your tank upgrade packages, to get it closer to, or even to best the preformance of the more expensive tank, for still less the money!
The South-Afrikan
Olifant MBT as a great example for this, as it's a modern tank that's basically just an upgraded version of the British WW2 centurion tank. Yes you heard that right! WW2!!
This also allows you to get the base cheaper tank first, as an emergency solution, and get the upgrade packages later, when you have the money.
Keep in mind, though, that, again, it's likely more economically viable, in the long run, to buy the better tank, straight away, than buy the cheaper tank, and upgrade it. But, if you have to, well, you have to...
Is that helpfull? c:
@Mn
Is the "creeper" a thargoid?