HO T5 4 bulb questions !!!!!!!

Ok so I have a $ foot HO T5 with 4 5400k veg and 3000k flower. I can upgrade my bulbs to 6400k for 17.95. The guy at the shop said I should upgrade my bulbs to maximize my yield. I know sales people will always try to upsell on anything they can so i wanted to get peoples opinion from a trusted source. This grow is on a budget and if i can save the extra money for something else that would be sweet. Do you guys think the upgrade would be a good idea. I'm growing 3 plants in a tent thats 4 foot wide 2 feet deep and 3 feet tall. Thanks all

IMO... haha... you or your plants will not be able to tell the dif...
For Less than $17, I'd buy a medium reflector, screw in a lamp splitter
and screw in two compact CFL's in max K and wattage you could find...
or... not, save the $17 and not worry about it...
Good luck...
Sales they want sales....