i got 2 23w 100 equivalent at lowes for under 8 bucks, think it was more around 6. it was a two pack. might be able to find them cheaper online but will have to pay for shipping and ups/fedex/usps have mandatory 4-6 ft drops in the shipping process. that cant be great for the bulbs. anywhere like lowes, home depot, walmart will have the bulbs you need at a good price. make sure you get daylight / around 5000k range and u are golden. depending on how many you want to use will depend on how many plants u will need to be vegging. i use socket Y adapters and put two bulbs around each plant. it can be done with one for each for sure though.