I say buy them. The games are great and at 10 you can't go wrong. If you want to get into the new games I think it would be wise you get into the older ones first. MGS3 and Peace Walker both precede MGS Ground Zeroes (which will be launched later), so if you want to get into that I think it is best you play those first.
MGS2 is nice as well. If you plan on getting Metal Gear Rising: Revengeance you will be introduced to the main character in MGS2 for the first time - Raiden. Note however that the gamplay in the latter is different from the games in the collection - stealth (collection) vs hack and slash (MGR:R).
EDIT
Well since you mentioned Batman, it is up to you really. It is a matter of taste. Note however that MGS HD costs around 29 USD while Batman is under 20. So if you chose to buy MGS and Batman AA later you'll save more (assuming you can't buy both now).
Playstation = The Beast from the East
Sony + Nintendo = WIN! PS3 + PSV + PS4 + Wii U + 3DS
