According to the rumor mill, the next iPad will be a substantial upgrade and will be priced similarly to the current model. On the other hand, the price of the current model should drop after the next one is released. In either case, it would be wise to wait a week or so. WiFi means a wireless router; if your home is already networked, it doesn’t cost much to add wireless. Also wireless is widely available in fast food places, coffee shops, etc. As things stand now, you cannot tether an iPad to a smartphone without modifying the iPad’s software.