UK Trail caters primarily for the budget traveller, who usually will stay at hostels. However, hostels do have some disadvantages, so let us assess other accommodation possibilities in Britain.
One would not normally stay in hotels unless money is no object or your employer is paying. Nevertheless, some hotels in Britain offer very good and reasonably-priced accommodation, especially in small towns, or in resort towns during the winter. Prices of hotels can vary enormously, from £40 per person (2006) to absurdly high levels. However a small hotel in a small town might well be priced in the lower B&B range (£25-30, possibly with shared bathroom).
The gradation: large hotels -- small hotels -- guest houses -- bed and breakfasts has no clear dividing lines. Problems such as noise from the bar, water pipes or outdoor yard activities are much more likely in hotels, even expensive ones, than in guest houses or B&Bs.
These don't really exist in Britain. There are one or two chains such as Travelodge which have motel-type accommodation near railway stations and main roads, and at motorway service areas. These are very expensive for one person at around £55 per room, but since they charge per room they could be reasonable for a family or group. People sometimes say that they have found very cheap offers for these chains on the internet; however, such offers involve making firm bookings in advance and usually apply to one night only. I have seen the budget chain Formule 1 in Britain, but it is not common.
This is a very popular form of accommodation. There are lots of bed & breakfasts throughout Britain, some on working farms. Modern regulations ensure that all are of a very high standard of cleanliness. They have most of the advantages of hotels, and are usually much friendlier. You nearly always get a room with TV and tea-making facilities. The cheapest ones offer a tiny room, but most nowadays have en-suite bathrooms. If you get a room for two, check whether it is twin (2 single beds) or double (1 double bed) if this is important to you. The breakfasts are nearly always excellent. They will offer you a large fried breakfast unless you specifically ask otherwise. These are excellent, though they can be very salty. Lighter breakfasts and vegetarian options are usually available. In any case you usually get juice, cereal, tea/coffee and plenty of bread or toast.
Typical prices (2006) including a substantial breakfast are: Single (if available) £35-40; double (a double bed) or twin (2 single beds) £25-30 per person. In seaside resorts with lots of small hotels and B&B's, off-season prices may be around £20-23 per person (single or double).
B&Bs are usually good value for 2 or more people. But if you are travelling alone, FORGET THEM, except in emergency! Single travellers, particularly if they are dressed for hiking, are not always welcome. "Sorry, we don't have any single rooms, and you wouldn't want to pay for a double, would you?" Translation: There may be a couple coming along, and we will make more money from them.
Even if you get a good deal from a B&B, remember that you never get cooking facilities (except for tea/coffee and biscuits). You can of course eat out, but remember that restaurant meals are very expensive. So all in all, a B&B stay is likely to cost a couple 2 to 3 times as much as in a hostel, a single traveller 3 to 4 times.
The B&B option is becoming relatively more and more expensive, much of which is for luxuries you might be happy to do without, such as en- suite bathrooms, 2 towels each, and TV in rooms. Remember that many hostels are now starting to provide private rooms without frills, at prices in the range (2006) £18-22 per person, and you can usually prepare your own food there.
Bed and breakfasts are usually more comfortable than hostels, the breakfasts are great, the hosts are often very friendly and sometimes happy to chat. Couples often like to stay at least a few nights in B&Bs, although many hostels can offer private facilities without frills much cheaper. But when comparing prices, don't forget the possible need for expensive restaurant meals. If you are travelling alone, hostels are normally the only price-worthy option.