I have a couple of brochures from 1999 including an S3 launch one and an S3 launch price list from May 1999.
S3 Basic car cost = £22,553.00
VAT = £3,946.78
Total = £26,499.78
S3 OTR = £27,149.78 (includes Delivery, Number Plates, Road Tax, First Registration Fee)
Options were (all prices ex vat & for S3 only. Some of these options were considerably more for lower spec A3s)
Acoustic Parking = £297
6 CD Changer = £343
BOSE = £442
Auto dip rear mirror = £125
Cup holder in armrest = £34
Cassette holder in armrest = £61
Cruise control = £277
Electric sunroof = £682
Armrest = £91
Luggage net = £63
Metallic or Pearl paintwork = £367
Sat nav = £1471
Heated seats = £301
Alcantara/leather upholstery = no cost
Cloth upholstery = no cost
Unfortunately I don't have a scanner so I can't post stuff easily - however an existing photo I do have is the launch colour choice
I also have a Jan 2001 price list and brochure - this is when they dropped the price and the OTR price fell to £24,770.
Most of the options remained at the same cost, new options included (again ex vat):
Symphony single CD player = £179.57
Phone prep = £339.57
Multi-function steering wheel = £123.40
Satnav plus (5 inch screen) = £2148.93
TV function for above = £600
Centre rear 3 point belt & head rest = £74
Side airbags = £400