Freesat uses the same sats (Astra 2A/2B/1N and Eutelsat 28A @ 28.2/28.5 E)
Only reason for re-alignmtent would be if you're using an old dish from the analogue days, as it would have been aligned to 19.2 E. If It's an eliptical mini dish you'll be fine.
I had some issues with my Freeview reception and hooking up the old Sky dish was a whole lot cheaper than having a complete new aerial system installed.
It probably hadn’t been used for at least 15-years, and because I needed a completely new cable run and drilling through the external wall I decided to pay to have it done. The guy had to check the LNB and was honest enough to say it was fine (I would have had no way of knowing one way or the other), and apart from spending another few minutes re-aligning the dish the whole job was done in less than 30-minutes for £66 inc VAT.
Even if your dish did need re-aligning, depending upon it’s accessibility you could do this yourself with a signal meter costing between £5-£20. If I hadn’t needed the drilling through the external wall this is what I would have done so it needn’t be expensive.
Don't worry about the dish alignment, its easy to set them up. I fitted my dish and aligned it with a cheap satellite finder, aligning the dish took about 5 minutes and took one attempt. That was with a newly fitted dish, yours will already be pointing in roughly the correct direction.
Don't forget if you are buying a freesat box like a Foxsat HDR you will need 2 cables to your dish if you want to watch and record different channels at the same time.