Depends who told you that you need orthotics - shoe shop? Doesn't sound as if it was someone who is really qualified to advise. If it was a physio, then I'd have thought that they'd have recommended you to a pod for an initial assessment.
As M.eldy says, not everyone who pronates needs orthotics. I do and I've been wearing them for years, but then I've ruptured tendons in my feet due to my overpronation - it happened through chronic wear and tear. When it happened, I was referred to a specialist and I now have to wear them permanently.
If Mr Puffy can recommend someone, then that's a good place to start. My pod (I'm down south, so no good to you I'm afraid) charges around £50 for initial consultation, then the cost of orthotics depends. Mine cost £200, are made of carbon fibre and last for years. My first pair were made for me in 2004 (when I ruptured my tendon), I found a new pod when I moved area and started running. I had some new ones made and she refurbished my old ones as the said that they were still very good and I'm still using them. She reckoned that I'd get 5 - 10 years out of them and I just go and see her once a year to make sure they're still OK.
If you genuinely need them, then it's worth paying for them, but if you don't, then get some decent shoes, but take the word of a properly qualified pod. If you've got ITB problems, then look at exercises as AP said, shoes may help pronation, but that won't prevent / cure injury.