I'm an indie game designer and have been trouble finding a reliable programmer to create my game (it's a SP and MP final fantasy tactics like game). I want to program the game to be cross platform so I am considering Love2D, java, or C. I am considering hiring a programmer to work on it for me since I can only do basic stuff. However, I work a normal day job like most people and can't afford to pay a lot. Before I commit myself to this option what would be a reasonable amount to offer for a project like this? Also, what would be a typical way to measure work (pay by milestones or pay by month?).

1. Why do you want the game to be cross platform compatible? Which platforms specifically are you trying to target? Why? What's the business logic behind it? If you don't know the answers to any of these questions, you really need to sit down and figure out why this is a necessary requirement and what you're objectives are. If you're committed to cross platform support, it's going to take some factor of X time longer to complete and ship your game. You'll almost certainly want to use a game engine.
2. Now you want to specify a programming language requirement as well? Why?! That almost guarantees that you're not looking at a specific game engine and that means your multi-platform support is going to be excruciatingly difficult and cost a lot of time and testing. My recommendation is sit down with your programmer and pick a game engine he/she is very familiar with.
3. Since you're working a day job, that's going to make things a lot more difficult for you and your programmer to complete the game. What happens to their progress if they have a critical question for you? Can they interrupt you at work or do they have to wait? How do you keep the pace of work smooth and seamless? What happens if you get home at night and are burned out by work and can't muster the energy to work some more on a game project? What if you lose your motivation/commitment to the project? What if that happens to your programmer?

4. You want to pay your programmer well enough to keep them motivated to keep working on the project. The precise amount of money that comes out to varies by programmer based on their level of experience, motivation, alternative offers, economic circumstances, interest, etc. The only way to figure this out is to talk to your prospective programmers.

Normal rates around here(western europe) for freelancing programmers are in the $50-$200 / hour range. I would expect US rates to be similar.

Freelancers have to pay for their own equipment, licenses, insurances, taxes, social security fees and put away money for downtime between projects, their retirement, vacations, etc (costs normally covered by an employer) and thus they will be significantly higher than a normal salary.

The success of any software project depends heavily on the quality of the staff involved, attempting to cut costs by going with cheap freelancers is very likely to backfire(inexperienced programmers will most likely require far more time even for simple tasks and are far more likely to deliver low quality code)

Throwing in revenue shares is an option if the OP is unable to afford paying market rates but he needs to consider the risk everyone takes when assigning shares. It is unfortunately quite common for "idea-guys"(not saying the OP is one of those, but they are unfortunatly quite common) to assign the majority of the shares to themselves while letting everyone else take all or most of the risk. (working for free or at a reduced rate is equivalent to investing money in a project).

a fairly decent way to assign revenue shares to a team of partially paid freelancers is to:

* give them 1 share * (TheRateTheyAreWorth - TheRateYouPayThem) for each hour they spend on the project.

* give yourself 1 share * TheRateYouPayThem for each hour they spend on the project

* give yourself 1 share * TheRateYouAreWorth for each hour you spend on the project.

* if you spend money on the project in other ways(servers, hosting, marketing, etc) give yourself 1 share per <insert_unit_of_currency> spent for that.

This gives everyone a share proportional to the risk they take and noone gets shafted, if you take a reasonable share of the risk(by paying a portion of everyones normal rate and/or by putting in solid, high quality work yourself) and keep the total risk other people take down you can attract and keep some decent talent even on a tight budget.