Here is a Westinghouse 15 watt daylight AC/DC bulb in a fixture.
A one cent start bid.

http://www.ebay.com/itm/Vintage-Fluorescent-Light-Desk-Lamp-Machine-Age-Mid-Century-Industrial-Art-Deco-/291238711455?pt=LH_DefaultDomain_0&hash=item43cf2e109f

Old Sylvania 15 watt in fixture.

http://www.ebay.com/itm/Vintage-Retro-Machine-Age-Industrial-Steam-Punk-Deco-Metal-Fluorescent-Desk-Lamp-/110831845389?pt=LH_DefaultDomain_0&hash=item19ce17c00d

A brass ender 15 watt bulb of a unknown make.

http://www.ebay.com/itm/RETRO-MACHINE-AGE-FLUORESCENT-LIGHT-or-DESK-LAMP-/201132275376?ssPageName=ADME:X:AAQ:US:1123

I like the gold ends on the old Gro-lux bulbs.

http://www.ebay.com/itm/24-F30T12-Gro-700-Sylvania-Gro-Lux-Florescent-/111341879102?pt=US_Hydroponics&hash=item19ec7e3f3e


A case of Durotest bulbs.

http://www.ebay.com/itm/Duro-Test-Preheat-Trigger-Start-15W18-T8-BIPIN-Fluorescent-Lamp-25-Pcs-VL9514-/400770375352?pt=US_Light_Bulbs&hash=item5d4fc69eb8

http://www.ebay.com/itm/Duro-Test-Preheat-Trigger-Start-15W18-T8-BIPIN-Fluorescent-Lamp-24-Pcs-VL9501-/361045937556?pt=US_Light_Bulbs&hash=item541003cd94


Need a few fluorescent fixtures?

Sold right after listing.

http://www.ebay.com/itm/Used-Fluorescent-LIght-fixture-with-bulbs-lot-of-100-estimating-/261584423015?pt=LH_DefaultDomain_0&hash=item3ce7a58867


Hard to find single 40 watt PH ballasts.

http://www.ebay.com/itm/THREE-Vintage-Advance-Fluorescent-Ballast-40-Watt-75-Amp-/251640638645?pt=LH_DefaultDomain_0&hash=item3a96f36cb5

You know what's interesting about all this ,

These sellers would make a lot more money if they just simply remove the vintage fluorescent bulbs from the desk lamps and sell the bulbs only ,

I have absolutely no interest in the desk lamps ,

But a single listing for a brass end cap F15T8 , fluorescent bulb ,you bet

Here is a Westinghouse 15 watt daylight AC/DC bulb in a fixture.
A one cent start bid.

http://www.ebay.com/itm/Vintage-Fluorescent-Light-Desk-Lamp-Machine-Age-Mid-Century-Industrial-Art-Deco-/291236174531?pt=LH_DefaultDomain_0&hash=item43cf075ac3

Old Sylvania 15 watt in fixture.

http://www.ebay.com/itm/Vintage-Retro-Machine-Age-Industrial-Steam-Punk-Deco-Metal-Fluorescent-Desk-Lamp-/110831845389?pt=LH_DefaultDomain_0&hash=item19ce17c00d

A brass ender 15 watt bulb of a unknown make.

http://www.ebay.com/itm/RETRO-MACHINE-AGE-FLUORESCENT-LIGHT-or-DESK-LAMP-/201132275376?ssPageName=ADME:X:AAQ:US:1123

I like the gold ends on the old Gro-lux bulbs.

http://www.ebay.com/itm/24-F30T12-Gro-700-Sylvania-Gro-Lux-Florescent-/111341879102?pt=US_Hydroponics&hash=item19ec7e3f3e

Need a few fluorescent fixtures?

http://www.ebay.com/itm/Used-Fluorescent-LIght-fixture-with-bulbs-lot-of-100-estimating-/261584423015?pt=LH_DefaultDomain_0&hash=item3ce7a58867

I agree.
I have no idea what I would do with any more desk lamps, but I sure would like to have some of those bulbs.
I am amazed but not surprised how many fixture sellers dump the old bulbs and replace them with new bulbs from Walmart reducing the value of the fixture to almost nothing.
Unfortunately it seems to happen a lot.