The 125g petsmart deal is probably the best full setup I’ve seen minus filters etc. Spending 1.5k to 2k is laughable, you can get that for roughly $500 brand new give or take a $100 - all in all not a bad deal. Facebook marketplace is pretty decent for that stuff too. But don’t spend anything above $750 for a full setup IMO in the 125g range.
I got a used 125 from a lfs for 200 and got an fx6 new on sale for $240, but adding lights, heater, sponge filter, substrate, plants etc I definitely neared 1k. And built a butcher block stand with galvanized steel for the legs for around $250. So the petsmart deal is a good deal, I wouldn’t get hung up on $100 bucks.