Costco is members only, but this seems a reasonable deal if you know someone with membership.
In the Costco Passport discount voucher booklet, there is a coupon for £30 off a Sonicare Elite double pack, making it £82.23 including vat.
However according to the staff, the price has dropped - but they will still knock off the £30, making it £63.43 including VAT.
From the box:
Includes 2 handles and 2 brush heads
1 deluxe holder
1 charger base (*Note - only 1 charger*)
Features of all Sonicare models: Smartimer, Easy-start, extra-soft bristles
This model also features: Quadpacer, Ergonomic tapered handle, Deluxe recharge gauge, Dual speed control, Superior cleaning technology.
Naturally whiter teeth
Guaranteed results in 28 days (or full refund)
#1 recommended brand by U.S. dental professionals
2 year warranty
This was in the Chester store, but all Costco's tend to have identikit offers.
Passport voucher expires Sunday 25/11/2007
Also, Costco do replacement heads for these at two for about £14.50 including VAT (regular price, not an offer).