Best, affordable equipment needed for tiny-batch brewing?

So like anyone fairly fresh to homebrewing, I have a thousand ideas I want to try and neither the time, money, nor equipment to do them all any time soon.

That's fine. There is a long life of brewing ahead of me.

Still, I'm impatient. I'd love to dabble with batches of one gallon, two gallons, or 2.5 gallons. Whether splitting a five-gallon recipe and trying different yeasts & secondary techniques with the same boil, or simply boiling in very small batches so I can quickly and cheaply try a variety of brews -- not to mention so I can brew every weekend if I want -- it will help me scratch the experimentation itch without bogging me down in fermenters and more bottles than I can ever drink.

(As it stands, I rotate between two bucket fermenters. Also have a glass carboy, but hope to have that filled with a long-term beer soon. And I have bottles coming out the wazoo that I can't empty fast enough without getting permanent lover damage.)

So what are my best options for fermenting small batches? I seem to recall reading that if you bucket ferment you can do 2.5 gallons in a 6.5 gallon bucket and not worry about all that headspace, as CO2 will fill it. That's good if I want to split a batch, though it would then also leave both fermenters tied up.

Are there tiny bucket fermenters, and if so, which are the best? I do have extra airlocks already.

In addition, any issues I should keep in mind if I want to pursue this?

Thanks!

Search on line for 3.5 gallon Food Grade buckets. Pretty sure they use the same lid. Or you could go the Carboy or better bottle route.

You can buy the 3 gallon plastic carboy/Better Bottle. It will cost you the same amount ($20) of a 6.5 gallon pail fermenter, but without the head space.
There is also this 2 gallon bucket for $6: http://www.northernbrewer.com/brewing/2-gallon-bucket-w-lid.html If price is a problem I would go with this option.

Excellent suggestion, and that's a great price. I planned to place an order with NB soon, anyway. That (or three) looks to be the perfect addition to my order. Thanks!

I only do small batches these days (2.5 gallons), and I really like it. I get to try a lot more beers that way. I used to make 5.5gal batches, but I don't have a kegging setup, so I was having to bottle like 60 beers, and then I was having to stock like 180 bottles to keep up with my batches. Now I bottle about 25 beers, only have 75 bottles total, so at any given time I can have 3 of my homebrews and not have like a million bottles laying around.

you should definitely try the plastic carboy. i don't like fermenting buckets just because the lids are such a PITA. my fermenting buckets quickly became bottling buckets...

i wouldn't suggest using the 6.5 gallon fermenters for small batch. you could probably get away with it and hope that the headspace is filled with CO2, but if your fermentation is slow to start then you really risk oxidation and if you're on a budget then you don't want to waste any money. you'd save more getting a smaller carboy or bucket after you wasted a batch of grain on a spoiled brew

I have fermented plenty of 3 gallon batches in my 6.5 gallon buckets and 5 gallon carboys, even letting them sit in primary for as much as three months. The only problems with infections I have had were from my own sanitation blunders. I have not had problems with beer turning into vinegar or oxidizing the beer.

That said, I do a lot of one gallon batches. I probably wouldn't do that small of an amount in a 6.5 gallon bucket just because it wouldn't make sense (for me) to occupy that much fermentation space with so little beer.

I buy those 4L wine jugs and use the wine for cooking. Once it is emptied out (I go through one every 3-6 months) it becomes a one gallon fermenter. I use wine a lot in my food so it's cost effective. You can also find one gallon apple juice jugs. You can turn the apple juice into cider/graff/apfelwine and quickly empty it out. The only problem is you will need to use something to limit krausen, otherwise you will blow out a lot of beer.