I have both Schwab and Fidelity accounts. I've been comparing TIPs prices from the two over the last week or so. It looks like Fidelity wins out pretty consistently. Here are the current prices for a few.
1/15/15 1.625% Schwab: 89.81 Fidelity: 89.054/89.770
1/15/16 2% Schwab: 89.97 Fidelity: 89.257/89.797
7/15/16 2.5% Schwab: 92.67 Fidelity: 91.92/92.58
So, even if you buy at Fidelity's ask price, you'll do better than you would with Schwab. But that's not all. For all my purchases on Fidelity, I've been able to get a price that was 3 or 4 basis points better than the Ask price. E.g. if I wanted a 2016/2% TIP, I'd put in the order at 89.50. After a few tries I would probably get it at that price. That's more than 1/2 percent cheaper than Schwab.
Comparing Schwab to Fidelity TIPs pricing
Comparing Schwab to Fidelity TIPs pricing
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