Our 77 Argosy has 4 reading lamps that require the 1383 bulb which run between $5 - $6 each locally. So I started searching the internet for cheaper bulbs. Found a place - Bulb Direct
They have the bulbs under the automotive or miniature section for only $1.71 each!!! And shipping is only $4.95 (UPS 2nd day air shipping). I placed my order for 15 late Thursday evening and they arrived today. They are incandescent with the bayonet base - identical to the GE/Sylvania bulb just cheaper. For $30 I got 15 bulbs vs only 5 bulbs if purchased locally.
They have a vast selection of bulbs for all kinds of uses. With your order you also get their catalog and they have a toll-free number for ordering or you can order on the internet.
Just wanted to let others know.