Hi Paul,
I certainly find a scope very useful for the more distant birds, especially the ones down at Saltholme Ponds, Teesmouth at Greatham Creek, The Headland and the Gares. Any coastal birds I suppose and at Low Barns Reserve.
From what your wife told me when we met a few weeks ago, it sounds as if you do get around quite a bit and would make good use of a scope.
Scopes come either straight through or angled. Some people say a straight one is easiest for people new to scopes, but I started with an angled one and had no problem. I also find it easier to use between people of different heights as you don't need to keep adjusting it.
One deciding factor must be whether you want the scope just for birding or whether you may venture into Digiscoping ie using a camera with it. If it's for digiscoping then really in our dull climate you need the high quality glass such Fluorite Hi Res or ED, depending on manufacturer and preferably a diameter around 80 mm, to let in enough light to get a high enough shutter speed.
If the scope is purely for optical viewing then some of the smaller 60+mm scopes would suffice. Your eye is less sensitive to the subtle differences between glass types. I used to have a Kowa 611 with a TSN 30WW which I found ideal for birding locally. It had the benefit of being lighter than the larger scopes ie more comfortable to carry about. Photo wise I couldn't get decent results, so I upgraded to the Kowa 823 with 32x eyepiece, which I picked up secondhand for £400.
Don't forget that with new scopes you buy the eyepieces separately, secondhand they usually come with one. Fixed ones for most scopes seem to be better for photos, but zooms from the decent manufacturers are just as good, certainly for just eye viewing.
Personally I think it's best to have a look through a few scopes either at a shop or whilst out birding - don't try the Leica or Swarovski though or you'll want one
and they're a bit pricey. I'd stick to one of the bigger manufacturers though such as Kowa, Opticron, Nikon etc.
Unfortunately we don't have many shops locally stocking scopes. There are two in Darlington and one in Middlesbrough, but ranges are limited. I travelled down to Harrogate for my first scope as there is a very good shop there selling new and secondhand scopes - it's the nearest decent optics shop to us and advertises in the bird magazines - Bass and Bligh. A good place to try out scopes is at one of the In Focus field events. They visit Low Barns Reserve at Bishop Auckland on 18th May ( they were there today!) or Washington WWT on 23rd April. They have a good selection of scopes. I actually rang them last year before a visit and they brought up a couple of second hand ones for me to try out too.
Once you've decided on what scope to get then there are several online suppliers doing new and secondhand scopes, such as Focal Optics who advertise on here. Bird Watching magazine is a good source for scope vendors.
Finally, your budget needs to take into account a decent tripod. A rock solid sturdy one is an essential, such as the Manfrotto range. A sturdy one could set you back around £100, above or below depending on whether new or used. You can usually pick one up second hand at a bargain price - our local shops sell them too.
I hope this helps a bit, but there is a lot of ground to cover.