Here is the Blue book skinny..
EA22 NUNO BETTENCOURT LIMITED EDITION
- single sharp cutaway folk style, spruce top, oval soundhole, bound body, five-stripe purfling, ninestripe rosette, mahogany back/sides/neck, 21-fret bound rosewood fingerboard with pearl wings inlay, rosewood bridge with white black dot pins, bound blackface peghead with screened signature/logo, three-per-side chrome Grover tuners, acoustic bridge pickup, volume/tone control, 3-band EQ, numbered commemorative metal plate inside body, available in Black finish, mfg. 1992-94. Note: at least one white in existence. Labeled “Platinum Edition” 1991 build date.
Grading 100% Excellent Average
N/A $475 - 550 $300 - 350
Last MSR was $1,000.
Your estimate of about 1,500 models built is as good a guess as any. Washburn did not keep very good records of that kind of info. The bad news for you is the demand for these guitars is not what it used to be. The Blue Book value has been at best static for years. But BB values are not always a good indicator as the number of guitars sold is so small. So getting an accurate average is difficult. Best guess, assuming the guitar is in really great shape you might get $550.