Well, if the whole fixture is too expensive, you can always just bypass the starter and run 115v to the pins in your existing fixture and throw in some of these:
$22/ each if you buy them in lots of 4, meaning about $176 to replace all your fixture's bulbs with LEDs. Instant start, long life, and you can choose warm, neutral, or cold. Although that's if you have a T8 fixture (I assume?) if you have T12, just shop around.
In any case, I just typed the keywords into Google shopping for both of these, if this is something you are actually interested in doing, you can shop around and get considerably better prices than that for panels. It's up to you