Well, that's ok. Let's divide the blinds debate into what is most practical for you (this can be subjective) and what's going to fly with what's left of your budget. To discover what makes most sense for you, and for the environment you are trying to create, let me ask and make the following general questions and statements to get you thinking...
What have you had, seen, or used in the past? What did you like or not like about them? What worked well for your needs? Do you need complete privacy? Do you need privacy at night or just during the day? Are the blinds for bedrooms or living areas?
Venetians are great in terms of controlling light and privacy by tilting the blades as you require. Roller blinds need less cleaning than Venetians however they are really just up, down, or somewhere in-between. There is no micro-light-adjustment-control with roller blinds in the same way as Venetians deliver
Sunscreen roller blinds are good if you need to cut glare back. Reducing UV-ray damage to carpets, floors, and furniture. These are also good when it's only daytime, not full nighttime, privacy you require
Sheer roller blinds provide soft ambient light during the day and still give complete privacy both day and night
Aesthetically: This is personal preference. Some people like the traditional look of Venetians; while other people prefer the ease and lightweight operation of roller blinds. We definitely supply more roller blinds than Venetians however there is no right or wrong here. You won't be judged! I personally feel roller blinds give a less-fuss-cleaner-more-modern-look however Venetians are far superior at micro-adjusting the light, the view, and your privacy throughout the day and night
Price related: Generally speaking roller blinds are more economical than Venetians. Roller blind pricing does fluctuate depending on your fabric choice though. Venetian blinds in terms of cost (lowest to highest) are: Aluminium Venetians, PVC Blinds, 50mm Wooden Venetians, then the mighty 60mm Wooden Venetians taking top position
Entry level sunscreen and blackout roller blinds are close in price to Aluminium Venetians. The higher end of sunscreen fabrics (Vivid Shade) comes in as more expensive than Aluminium Venetians but more economical when compared to PVC Blinds. Blackout blinds using top price fabrics, like Gala for example, are usually still more economical than PVC Blinds
More simply put (lowest to highest price wise): Aluminium Venetians, basic Sunscreen and Blackout blinds (grouped together), then Sheer roller blinds, followed by top end blackout roller blinds, then PVC Blinds, 50mm Woodens, and lastly 60mm Woodens with their bold aesthetic. I used a sample size of 4 blinds with random varying sizes to calculate the above ideas of cost in relation to each other
Please use above as a rough guide only as there are factors that will push and pull price in different directions: e.g. blind widths, sizes, fabric choice, number of blinds, motorisation, etc. As a suggestion: get a quote for your most desired solution first. We can always work back from that point with alternative quotes. I'm happy to do that
PS: We do shutters, awnings, and outdoor blinds as well. These are all higher priced solutions as I'm sure you are aware