Thanks for submitting your thread. I recently had this question asked by a distant family member. A lease option to purchase, as I will assume this is your question, is a three year plan where sellers and investors market property to target folks with less than desirable or bad credit to seemingly purchase a house within a short time frame. Statistically, these type deals rarely make it t term and the sellers know this. The option terms are so strict and rigid that it is nearly impossible for a potential buyer to actually own the property. For example if you are late on one payment or loose your job/income and can not pay, the contract is void---no exceptions will be granted for any reason. Keeping this in mind it would be a huge gamble with your $3K.
As mentioned below, the smarter choice would be to hold onto the $3K and build on to it, or pay down debt to build up your credit. The housing market will more than likely remain the same for some time to come and this will be to your advantage. Good luck!