Hi,
Yes, to be able to run our plug-ins on 3ds max 2017 & V-Ray 3.4, you'll need to upgrade and you would be charged the usual Renew Subscription fee (we truly believe the software is "value for money" enough and the renewal pricing is set to really reasonable amount).
Let me add, that you can renew your subscription at any time to get access to latest upgrades - the "active" subscription plan period would start from the day, when the renewal will be purchased - the new subscription end date will be calculated from that day (day of renewal purchase + 1 Year / 3 Years).
Having the subscription plan Active, gives you not just access to latest releases or beta versions, but also premium technical support and prioritized incident management, including first response to your issues within 1 business day, and usually much faster than that and special subscriber-only promotions and discounts.
Best regards,