I saw this cute little cover in the Matthew Bennett sale 365 today. At first I thought it might be a $2 Columbian that was used accidentally instead of a 2 cent Columbian. This is a local cover with no apparent registration markings so the rate should be simply 2 cents. The $2 is close to the same color as the 2 cent (in a pouch of one cent blues and three cent greens, the $2 brown red and 2 cent brown violet could be easily misidentified).

(I have a $2 lamp #1611 on commercial cover along with a 37 cent stamp during the first class 39 cent rate that I figure the $2 stamp was mistaken for a 2 cent make up rate).
But alas, Siegel sale #952 has a solo $4 and solo $5 cover to the same addressee. For the $5 cover, they offer this humorous comment in the description:
"Only a small part of the postage paid was necessary for the letter to reach its intended destination. The recipient, Otto G. Mayer & Co., was a shipping and commission firm that started business in 1835. However, by 1902 they were insolvent and declared bankruptcy, due in part to a sharp decline in the price of rubber. Perhaps the high cost of this stamp contributed to their bankruptcy as well."