Ah, I get it, dopplers can be pricey! Have you tried checking Marketplace or OLX? A few of us mums have found decent ones there, though honestly I'd be a bit cautious kasi minsan hindi sure kung gano ka-accurate na pa after being used. Maybe ask the seller kung gaano katagal ginamit at if they still have the manual, kaya mo ring try checking sa Lazada or Shopee para sa affordable new ones, sometimes may sale sila, and at least may warranty pa. Let me know if you find anything, mama!