I bought a bow, cheap, online and sight unseen. It was made by a not-too-famous bowyer and set me back $200 new. It isn't the straightest, prettiest, or most efficient bow out there. Not by a long shot.
My point is that after a while I got to where I put an arrow where I was looking and it's only gotten better since. SO, figure on this: get a bow you can afford that's in decent shape. Buy a bunch of arrows and have someone help you with the tuning (this is the hardest part) then get out there and shoot!
No bow is perfect, and the fancier they are the better they shoot out of the hands of someone who has taken the time to master the form, but it won't make a bad form good. Whatever bow you get don't second guess it (unless it's too heavy for you to draw without shaking or causing yourself pain). Learn to shoot it and you'll know when your form is no longer an issue and whether or not you need to upgrade. Until then remember that traditional archery is an organic thing, made traditionally with wood that has all kinds of inherent variability. The only constant in this game is you - how you draw, how you focus on a spot, how you release, etc.
BEST OF LUCK and know that you've got a family here and a MOUNTAIN of knowledge to glean.