A582-“1989 UK Royal Mail First Day Cover Christmas800th Anniversary Ely Cathe

Title:
“1989 UK Royal Mail First Day Cover – Christmas 800th Anniversary Ely Cathedral (14 Nov 1989)”
Category:
Collectables → Stamps → Great Britain → First Day Covers / Royal Mail Commemorative Covers
Condition:
Excellent – Cover appears clean and intact, stamps affixed and cancelled 14 Nov 1989 first-day of issue as shown. (Please mention any small flaws such as minor toning, bends or envelope wear if present.)
Item Specifics:
Issuing country: United Kingdom
Year of Issue: 1989 (14 November) 
Set: Christmas – 800th Anniversary of Ely Cathedral 1189-1989 
Format: First Day Cover (FDC) with all five stamps/scarce charity surcharge versions
Designer: David Gentleman 
Denominations / Surcharges: 15p (no surcharge), 15p+1p, 20p+1p, 34p+1p, 37p+1p (or similar) — check the exact values on the cover
Cancellation: “First Day of Issue” cancellation dated 14 Nov 1989 
Presentation: Printed envelope showing “ROYAL MAIL FIRST DAY COVER CHRISTMAS ELY CATHEDRAL 1189-1989”
Mint / unused stamps on cover still attached etc
Any certification or provenance if available (if you have original envelope back flap, sender address etc)
Valuation & Recommended Price:
From available market data:
The stamps alone mint appear to trade for very modest amounts (for example a mint set listed around £1.70 on one specialist site) 
A gutted unmounted mint gutter version on sale for ~£3.99 on eBid. 
A used single stamp event listing shows extremely low value. 
Thus, as a First Day Cover the value is modest but attractive for thematic collectors of British FDCs.
I would place a valuation of around £10-£15 (if in very good condition) as a realistic fair value.
eBay Listing Price Recommendation:
Buy It Now Price: £14.95
Auction Option: Start at £5.00 with no reserve (to encourage bidding) and consider a Buy It Now option at ~£12.95.