I recently planned my own DIY Umrah, and finding clean and affordable accommodation was definitely a priority for me too. In Makkah, I found a place called Al Tawfiq Plaza Hotel, which was quite decent and within your budget of 70 to 100 SAR. It’s not fancy, but the rooms are clean, and it’s only a short walk to the Haram, which was really convenient. In Madinah, I stayed at the Al Ansar New Palace Hotel. Again, nothing luxurious, but it was clean and comfortable, and close to the Prophet's Mosque.
It reminded me a bit of the time I stayed at the Blue Mountains Accommodation in Australia. Though it's a different experience altogether, both places had this homely vibe that made me feel welcome. When booking your hotels, just make sure to read recent reviews online, as they can give you the most up-to-date info.