Hi Bob, welcome to the madness!
Be very careful going to flea markets and yard sales to buy used, (or even new), router bits. make sure they are REALLY sharp and don't have any nicks or scratches or burn marks. Also, watch out for the unscrupulous vendor that will purposely take the OEM bits out of a set and replace them with some junk made of spent shell brass from Nigeria or India or elsewhere.
I went to a flea market awhile back and watched a vendor remove the few good bits in an MLCS Katana set with some from a set made by 'GRIP' that were in a wooden box. He then marked the MLCS box at $75.
I waited until he was off to get some more food to stuff in his pie hole and went over to talk to his girlfriend. I asked her if they had any cheapo router bits and she showed me a number of the GRIP boxes of different sets. I looked at about 10 different sets and saw they were all either MLCS or Amana or Eagle America or Freud, and still had the original price tags on them. I bought 4 sets that day, all in the GRIP boxes, but all were well made, high quality bits that the vendor had swapped out. Total cost to me was under $100. One of the sets was a raised panel set from MLCS Katana.... $175 value and I think I paid $40 for them. All of the bits I bought were brand new.
Unethical? yup, it probably was on my part. Unethical on his part? It certainly was.
Grip tools are made in multiple places, and I do have some of their router bits, and they work well, but I paid $30 for a 15pc set and they are used only for rough cutting.
Learn what color coating is used on each brand of bits.... it's not always the best way to tell, but it is a quick check to see what you are getting.
Well if it floods my house you better have an ark handy.
Thanks for the tip about carbide bits, gonna hit the flea market/yard sale scene this weekend and see what I can come up with. Still need to look through the web and figure out what all these bits are for.