I have extensive experience within ISP and I can assure you that a /19 is not easy to get those days, it's a long process with RIPE/ARIN.
The price is the most painful point, it's getting up to 15-20$ per unit.
You can try your chance with the ipv4 auction websites.
IPv4 addresses will cost you more as there is less availabilty of these IP addresses.
Even then, hosting providers do provide more IP but you have to go through the RIPE verification
Hey looked into getting IPv4 space directly from RIPE APNIC and ARIN but the waiting list is over a year. Dose anyone have any suggestions on how to go about this.
For such a large chunk of mails, you may have to wait and nothing else to be done I guess.
Do you have already any running business or just planning to start ? If just starting, then I will suggest to start small and then once ip's are ready you can move over to those.