If they're the 215hp injectors it's a great price. 180s it's OK. 160s don't bother. Is your truck a 5-speed (came with 215 injectors) or auto (came with 180 injectors)? It's good to upsize, but there's no sense in downsizing (putting 180s on a 215 truck).
At 150k your stock injectors should still be good, although I've been told at that mileage it would be a good time to have popoff pressures tested. If you need to replace injectors consider getting a nice upgrade from Dyno-Mite Diesel, Piers Diesel, or a number of other vendors.
If you decide to stick with the injectors you have, it would be worth your time to remove them for no other purpose than to clean the deposits off the tips. 12-valves tend to accumulate deposits on the tips a lot worse than 24-valves. The tips on my '98 looked really bad when removed at 145,000, and downright horrid on my '96 when originally pulled at 353,000!
Vaughn