Measuring love by monetary value is just wrong in my personal perspective. A good gift is a good gift no matter the cost unless one's partner is the "absolute materialistic" type. For me personally, I think DIY gifts is much better than things one can just buy because time spent to DIY is worth much more than money.
For instance, one Chinese friend of mine is writing her own 上林赋 to give to her boyfriend on Valentine's Day. 上林赋 is a Fu ("rhapsody" or "poetic exposition", according to wikipedia), and it's a very long text with 4,184 Chinese characters. It is said that "if you write out 上林赋, you will get the love of your heart" so that makes it a perfect Valentine's Day gift. She bought a scroll-like paper, which is not very expensive to replicate the ancient text look, and she is writing it with a modern ink pen (which is easier to use than an ink brush, but still not as easy as regular writing). It takes hours to do so; she worked on it till 1AM - 2AM every night for the past few days and she's not done by now. But I think the time and work she spent on this is worth much more than say, a jewelry she can just buy, even if the jewelry is worth a lot of money.
!PIZZA