Go all-grain, and do smaller batches. This will require you to brew more often, thus gaining more experience with all-grain, but without the need for fancy equipment, and fewer bottles to fill at one time. You can very easily brew 2.5 or 3 gallon batches using BIAB. Doesn't cost a thing really, and in fact will save you a lot of money over extract, AND it tastes better. Then after you gain some experience with all-grain, get the equipment for bigger batches, do a few batches at that size, and then when you get tired of bottling 50 bottles at one time, get your kegging equipment.
Or, go the other way, buy your kegging equipment now, but just keep it on the shelf for a while since you can simultaneously start brewing small batches all-grain BIAB without spending an extra dime. Then when you've got the cash and experience to start brewing 5 gallons all-grain, you can worry about kegging, and you'll already have the stuff AND the all-grain experience. How's that sound.