I am about to join a flying club that is based at DVT and CHD. In CHD, they have an IFR-GPS Archer that rents for $78/hr wet tach (around 1980 model). They have another archer (same price) up at DVT, and a really nice new 182 and Piper Comanche (rotated between DVT and CHD).
Typically you get about 1.0 hours for every 0.8 of tach time, so the equivalent rate is $62.40 an hour wet. Most of my flight time was with a club that charged tach time, and I found it closer to 0.9 for cross countries, but have gotten it to as low as 0.5 for touch and go's. So If you just want to do some night touch and go's, you can get the rate as low as $40 an hour! If you are just time building, keep the power back. Instead of cruising at 2500rpm, cruise at the bottom of the green arc. And do lots of touch and go's and approaches.
The two things about this club are:
1. They charge $125/month membership fee. Lets say you flew your 50 hours in 2 months, that is basically an extra $5/hr onto the price. Nothing major.
2. They require a $4,000 refundable deposit. That is essentially your share price. If you have it, pay it, and you'll get it back when you leave. If you don't have it, there are still two things you can do. First, you can tell the club your plan, and draw against that balance with your flying (and get the balance back when you leave). They may or may not like that, but it is an option. Other thing is just take a short term loan and pay it back in 2 months. Even at something like 8 or 9%, it won't cost you more than $100 in interest over that time frame (or $2/hr at 50 hours of flight time).
You can probably get your 50 hours of time at this club for $2,500 to $3,500 depending on how you fly the aircraft.
If that doesn't work out for you, the only other good place I know of that rents an airplane for cheap is at Scottsdale. Southwest Flight Center. They have a 152 for $84/hr wet hobbs. I am not sure if it is IFR though. Also, Westwind up in DVT has 2 older 172's for $99/hr wet hobbs. Flight instruction (for your checkout) is about $60/hr at these places, as opposed to around $30/hr in that club. Ask about block rates.
For some reason, Phoenix seems to be the most expensive place for renting airplanes (even though it is by far the cheapest area I have ever lived in). I hope this helps. If you find any really good "secret" flying clubs, please let me know!