Thoughts?

This will be our second. Our daughter will be 2 years and 4 months when our next is born, and will be in a toddler bed by this time. Her crib converts to one and later as part of a full-sized bed, and I always planned to convert her crib and buy the new baby a new crib and mattress of his or her own. My MIL (slightly overbearing) knows I want this but keeps offering to buy our daughter a toddler bed so we can reuse our crib for the next. This would save us money, which my husband keeps bringing up, but we can comfortably afford the new crib and while I have nothing against hand-me-downs, I like the idea of giving each baby a fresh, safe as possible sleep space. Am I being a brat? Should I accept the offer of a toddler bed from my MIL or keep turning her down? Moms of more than one, what did you do or do you plan to do?