You don't need to "worry", but you DO need to become fully informed about these costs before committing to a price or the overall transaction, particularly if YOU are the one paying all of the closing costs in any given transaction.
Resale timeshare closing costs differ considerably from the closing costs involved with other types of real estate, particularly where a mortgage (and a need for title insurance) might be involved. Accordingly, the info you reportedly got from Northwood may not be directly or particularly applicable for a private resale timeshare transaction. Anyway, some specific details follow on typical costs:
1. Depending on the resort or "chain" / system, there is very likely to be a mandatory "transfer fee", typically $75 -- $100 at smaller independent facilities, $299 for any Wyndham deed, at least twice that latter amount (or more) for transfers in the Hyatt system. This transfer fee is completely unrelated to (and completely separate from) any actual deed preparation and / or deed recording costs.
2. Issuance of an "estoppel" letter, which documents under resort (or its' management company) letterhead and signature, the current owner's account status (whether there are unpaid fees, any liens, etc.) can be anywhere from no charge at all to $150, depending on the system or management company involved.
3. Deed preparation work and deed recording costs (recording fees vary by location and County) and document stamp costs (if any are applicable) will generally collectively cost somewhere between $150 -- $350. Anything more than that is frankly excessive, although many "eBay reseller closers" routinely charge in excess of $400.
4. Some closing companies charge an additional fee to have the buyer funds held in an independent escrow account until closing. Sometimes it's a $50 charge, rarely is it more than $100, sometimes there no escrow charge at all. This cost tends to be influenced by whether or not the closer has a working affiliation with an attorney's office.
I hope this helps. You need to ascertain who in any given transaction (buyer or seller) is going to pay these costs.
KC