First of all, any holster that's worth using for even one day, will be a quality holster. Otherwise, just stick it in your waistband. That said, there are some good holsters for around your price range.
This is what I carry my 45 in:
Yes, it's OWB and no, I don't have any trouble concealing it. Yes, it's about $100 and that's more than you want to spend. However, it will last you for the rest of your life and will increase the value of your gun should you want to sell it. Very few $50 holsters will add value to the gun in a sale.
If you're going to need the full size gun now, you'll need it sometime in the future. Why not get the right holster the first time?
R Grizzle Leather - Home
Failing that, consider an Aker:
http://akerleather.com/ They usually have something in stock.
Failing that, consider a Safariland 5198:
Law Enforcement Products | The SAFARILAND Group This is the least expensive holster that I would recommend to anyone. It falls in your range, but I'd still look to the others first.
In the end, it's your money and your life. Do what you want. These are just some ideas from me.