I recently got into optics as well when i got an 870 Wingmaster. I opted to go with an Aimpoint H1 and couldn't be happier with it.
I went with an Aimpoint because I wanted something that will last me for years and not have to worry about it breaking. There are cheaper red dots out there but they may not be as durable as an Aimpoint. The way i rationalized it, you get a $200 red dot and it breaks on you, you either go with another cheap $200 red dot and risk it breaking again or you decide to spend the $500 on an aimpoint. Either way, you end up wasting time and money, might as well go with the Aimpoint to begin with.
Besides, in the future, should you decide to mount it on another long gun with more recoil than a PCC, a cheaper red dot may not be able to withstand the recoil.
I've put about 50 rounds of slugs and about 50 rounds of 00 buckshot since getting the red dot and it has functioned flawlessly and maintained zero.