I am a rollie smoker, I was smoking 10-15 per day. With the purchase of an eGo 4 weeks ago my smoking dropped overnight to 4 a day. I started with a very basic starter kit, I got one top bit (clearomiser) and one battery and 2 juices for £10 from a shop in Preston town centre.
After a week I decided it was clearly worth the effort and I joined this forum and started researching. Here are a few of my conclusions so far.
The eGo clearomiser (top bit) has a lifespan of approximately 3 weeks, though that can vary hugely depending on quality. Price often isn't an accurate guide to quality as some arsewipes buy the cheap ones and sell them for top whack. Buying from a reputable online, UK based vendor is your best bet, and the name myepack comes up an awful lot.
Juice also varies a great deal in quality and UK based online vendors are again a good place to start, prices vary from £2-£7 approx for 10ml. I would suggest looking for something around £4 if you want to order that way, though I found the cheap juice I got with my kit to be fine as I tried it before I bought it so I knew I liked the flavour. I reckon I was using about a bottle a week to begin with, but I think it is a little more than that now.
I looked at the options of buying extra batteries and clearomisers and continuing with the eGos, but I decided it didn't make financial sense. By upgrading to a clearomiser or tank with a replaceable coil the initial outlay is higher but the maintenance cost in new coils is far lower. There are lots of forms to choose from and you will need to do a bit of research to find out what will suit you best. Variable Voltage/Variable Wattage devices are repeatedly suggested as the best first upgrade from the eGo.
Making your own juice appears to be another way to reduce costs and it is an area I am currently looking in to. I am trying to buy juices from companies that sell a premixed concentrate, so that if I find ones I really like I can reduce costs by mixing my own.
Vaping in pubs is basically at the discretion of the landlord, some are very happy for you to vape indoors and some would prefer you didn't. It is always polite to ask.
I think the sequence I have done things in has worked pretty well, so my advice would be to buy a cheap eGo kit ideally at a shop where you can try the juice flavours first. If after a week things seem to be going well look to upgrade your kit rather than buy replacement clearomisers for the eGo.
Hope this helps