You have lots of great choices. **** had some listings this week for Martin Bamboo Viper and Savannah longbows that were new but went for half of retail. Minor costmetic blemished.
It is probably safest to go with one of the brand names that you recognize rather than guess as to whether what your buying is of quality of not. Again, you have many many choices and everyone has their favorites.
Google the words craigslist search. You will find a listing for a craigslist searcher that will search nationwide listings. Just type in the word longbow or a specific brand of longbow and do a nationwide search. Play around with the keyword searches.
My most recent trad bow came out of that type of search and it was 20% of retail price. I am extremely pleased with the purchase. Just be wary, ask questions, speak to the seller by phone if you cannot see the bow in person. Use your best judgement.
Remember that the budget for the bow will include all of the necessary items that come after the initial cash outlay of the bow itself. Left over budget for high quality arrows, quiver and other gear is important. If you save enough on the bow purchase, you may even have enough to cover lessons if needed.