3 years later the HP 35 came out for ~ $2300 in today's dollars, was pocket-sized and had trigonometric functions.

[edit] In 1968 the HP 9100A (which was programmable and had trigonometric functions) was $5000, or $35k today.

>$900 in 1967 is equivalent to $6,776 today!! And this was considered "cheap"??

Yes, for 1967.

I considered buying a nixie tube clock recently.

Those nixie tubes aren't cheap!!