Hmm... since I've lived in both the US and the UK (in fact am off to the US in two weeks for the holidays) here's my take on the cost/scope of the fishkeeping hobby in the US:
Some things definitely are cheaper in the US, particularly hardware, but the difference isn't really all that great. A lot has to do with the brands of things and the sorts of kit being sold. For whatever reason, "hang on" filters are really popular in the US, though these seem like a total waste of time to me. Canister filters on the other hand are quite uncommon and tend to be expensive, especially the better-made brands.
The US fishkeeping business is somewhat more dominated by pet shop chains than fishkeeping specialists. While the UK does have pet shop chain stores, these are still a relatively minor part of the business, especially compared with the big fish/pond chains like Maidenhead Aquatics and World of Water. While there may be the odd bad Maidenhead Aquatics store out there, for the most part they are very competently run and offer a wide selection of fish. The pet store chains in the US tend to focus almost entirely on "bread and butter" stuff, and if they have things like African cichlids or oddballs, the quality of information offered is often less than satisfactory.
The US fishkeeping hobby really splits into two major segments: marines and community tropicals. There's relatively little demand for (decent quality) African cichlids, L-number catfish, oddballs, brackish, etc. The assumption is often that once a person has kept community fish, they'll "upgrade" to marines. In the UK the hobby is more diverse, and it is much easier to obtain wild-caught fish here than in the US where a most of the fish offered are captive-bred.
There's almost no demand for planted aquaria in the US. Yes, there are some American aquarists who keep 'Dutch' or 'Amano' planted tanks, but as a share of the market they're very, very minor. Obtaining better quality plants and the gear required to keep them is significantly easier in the UK. (To be fair, this is because most of this gear and some of the plants come from Europe, so it's simply a question of cost.)
American fishkeepers -- broadly -- have fewer scruples about using live feeder fish to feed predatory fish species. In the UK this practise is relatively uncommon. There's also more demand in the US for things like dyed glassfish and hybrid cichlids.
The mail-order fish trade is a much more mature business in the US than in the UK. An American fishkeeper will have relatively little trouble ordering fish online; in the UK this is only now starting to happen.
American fishkeepers will also find it much easier to obtain native freshwater or marine fish for coldwater tanks. This aspect of the hobby is hardly developed at all here. On the flip side, both the US and the UK labour under various laws that restrict the trade of certain species. American fishkeepers can't get Asian arowanas, snakeheads or (in some states) piranhas; British fishkeepers can't keep most coldwater Asian or American fishes.
It's perfectly possible to enjoy fishkeeping on both sides of the Atlantic, but I have to say that for an aquarist interested in non-community tank freshwater fish, it's probably easier here in the UK. American aquarists on the other hand benefit from lower hardware costs, so keeping marine fish is cheaper and easier on that side of the Atlantic.
Cheers, Neale
jeez...how much is it there? i mean i fill up my tank 2 times a week and spend $100. how much is it there per gallon/litre?
