It took me half a decade but I am getting to finish up projects. I have a 20" 1500 in .308, a SWFA 10x42 that I just need a scope base and rings to make an actual rifle out of it but there are a lot of options, from the Nikko Sterling on legacy sports website for $20 to $70 for other companies.
I don't think I would need it but I heard just get 20 moa by default, I just want a 1913 base that is good enough to work. What differentiates a $20 Nikko and the $50-70 Outerimpact,Nightforce,Talley,Burris, or those more expensive ones from each other?  
I would rather pay $20 than $50 if it works about as well, but if it's junk I don't really care paying a bit more, so I got no clue what to buy. Same thing with rings, I would like 2 piece ones, I would rather spend $30 than $70 but there are about 1 billion options and I have no idea what falls into junk, serviceable or overpriced for what I want.

I don't have a frame of reference for what is considered decent and there are so many options at the similar price points for both rings and bases so it makes it difficult to know what's what.
The Nikko base was red flagged but it was on Legacy's website so I thought it was worth the ask.
Another example, I know monstrum is considered airsoft tier, but visually compared to, Burris Xtreme Tactical, Vortex $50 rings and the SWFA rings, the $35 monstrum pro visually in terms of machining and finish look better than some of those I mentioned, so does that mean everything listed is junk? I know the answer would be yes for some considering how much any part of a high end set up would cost, I'm not saying I would buy the monstrum ones, but all the lower end stuff has that generic import look to it so I have no idea what's good or not.
Its a $220 rifle, $200 scope and a $270 stock so I can't imagine I need $150 rings to just have something fit for purpose.

Is the 20moa base detrimental if not being used at extreme ranges? Even finding 600 here would be pushing it, so I wouldn't imaging going to 1000 much.

Just a note that I saw on a Howa picatinny base, I would assume it would apply to any similar base.

"The 20 MOA base can be used to gain more usable elevation in your scope which can be a benefit for long range shooting. It is recommended that your scope has a minimum of 50 MOA max internal adjustment if it is intended to be zeroed at 100 yards."

I bought a Nikko base for my Howa .223 coyote slayer. It looked fine, but in actuality, the measurements on it were way out of proportion. Some of the slots were as much as .010" wider than others and a few were .005" deeper. That may sound like nothing, but it may as well be a foot, that's how much it affects zeroing.

A friend gave me a Monstrum rail. I measured it and found it to be much improved over the Nikko. Less than .002 overall differences.

Neither compare to a Leupold rail I have for Rem 700 LA (measures +/- .001" or less overall).

My take is a Monstrum is fine for a hunting rifle that you won't use for more than 500 yards, but if you want it for a long-range gun, spend the money.