Estate agent fees are a % of sale. Depending on area, and agent used; anything from 1% to 2% of price would be standard. Remember it's plus vat. Marketing outlays for photos, brochures, and online listing will run into a few hundred paid upfront.
Solicitor, expect about 1500 + VAT and outlays for each transaction. You'll get cheaper (and more expensive). But cheaper isn't always better.
Including outlays, budget for about 2k sale and 2,500 purchase. Purchase outlays will depend on whether it's Land Registry or Registry of Deeds.
Stamp duty 1% on purchase (assuming it's residential, up to 1 acre).
House survey (400), and valuation (130) on purchase.
Add a few grand for a skip to clear house, storage unit between moves, and to hire a van for the move.
I also spent a few grand tidying up the house before we put on market - quick paint inside, etc.
I'm sure others will think of more.