It's plausible that there is a macro for just about anything you can think of. Now if that macro is publicly shared here or on any other website is another question.
While I don't personally know of one designed to do such a thing, it's wouldn't be hard to make a macro that searches for items that meet certain criteria and then purchases them for you. Just be a matter of sitting down and writing it based on how you want it to work.
If you are having trouble with bazaar.mac or bazaar2.mac you should post on the resource for assistance with those macros @Frimp . Bazaar.mac has a buyer mode, I haven't added one to Bazaar2.mac, I didn't code the buyer mode of bazaar.mac but I do maintain the code. Therefore if there is an issue with it, please post on the discussion page for the resource with what it is and isn't doing so that I can troubleshoot the code.