New tyre advice please.

I'm a very frequent reader but rarely even log in never mind take part but I have a question.

My daily ride is a Raleigh Urban 2. Not a fast bike, but a comfy one that gets a bit more bad treatment than it deserves (like being dragged along dirt tracks that are 4 inches deep in mud poor thing ).

So far all I've had to do for it is keep it clean, greased, index the gears and change the brake pads. The back tyre just got to end of life with red showing through at a couple of points along the centre track.

It is currently a Raleigh branded 700c 37 puncture resistant that is smooth with a few small grooves. I'd like something similar and reasonably priced as I'm currently unemployed and paying bedroom tax too so pretty much on the breadline. Obviously the 37 cross section has a few mm leaway and I don't care about the make (this isn't a fast road bike!). Having only had 1 puncture in 6500 miles (and that was going over the usual recently flailed hawthorn scattered across the track) I really want puncture resistance.

Can anyone recommend a good budget tyre and seller too? I got really confused trying to google and go through some of the sites.